At present, tire pressure monitoring and alarming devices available in the market mainly are in form of electronic sensors which sense air pressure within a tire via electronic chips. The electronic chips need to be powered for 24 hours a day, thereby causing large power consumption. As a result, the battery is to be exhausted easily and needs to be replaced frequently. It is inconvenient for users. Particularly, once the battery is exhausted and is not replaced by a user in time, the alarming device will not work normally, thereby resulting in potential hazards. In addition, electronic chips have certain requirements on the working environment, and are likely to break down when working in severe environments and thus unable to work normally. Furthermore, the electronic chips for sensing air pressure are high in cost.